Preliminary in vitro Studies of Melanophore-Principle Activity of the Pituitary Gland.

Abstract

(1) In vitro experiments indicate that one of the biological mechanisms of the melanophore hormone is that of an accelerator of an oxidase system such as tyrosine-tyrosinase. (2) The pressor hormone, and perhaps the oxytocic hormone also, act to inhibit this oxidase system. (3) Melanophore hormone has been obtained from anterior sperm whale pituitary which results in a black coloration of hypophysectomized frogs when 1 cc of a 1 × 10^-6 dilution of this hormone is injected. The black coloration persists for at least 24 hours.